This is a request for competing continuation funding for the study, "HIV1- related Neuropsychological Abnormalities" (ROI-MH45311), a project which evaluates the longitudinal course of cognitive function among a population-based sample of HIV-infected individuals. Although cross- sectional data demonstrate that symptomatic HIV+ individuals have increased rates of neuropsychological abnormalities, little is known about the progression of these deficits. Interpretation of most data is difficult because many studies focus on highly motivated volunteer subjects. Further, while the neuropsychological abnormalities in HIV+ individuals have been studied in relation to underlying neurologic disease, relatively little is known about the extent to which cognitive abnormalities may also be produced by diagnosable psychiatric disorder, or about whether - in the presence of established neurological disease and/or psychiatric disorder - other factors (e.g., HIV-related medical and psychosocial factors) act to increase HIV+ individuals' risk to display neuropsychological deficits. By delineating predictors and risk factors for neuropsychological deficits in HIV+ individuals, we may refine our models of the pattern of neuropsychiatric effects operating during the course of HIV infection. The Allegheny County Neuropsychiatric Survey evaluates the neuropsychological, psychosocial, and neurological consequences of HIV infection and AIDS among HIV+ community residents seeking prima medical care. The purpose of this application is to request three years of continuing funding to: enrich our current sample of HIV+ recruited men through our sentinel physician network, to add 50 new HIV+ women and 50 HIV- female controls from the same sentinel physician network, and to complete baseline, six month, and one year follow-up examinations of neuropsychological, psychiatric/psychosocial, and neurological status. This study data are relevant to the NIMH-mandated key research questions concerning the need to obtain an accurate understanding of the causes and predictors of HIV-related neurobehavioral impairments, addressing gaps on our current knowledge including: 1) how the virus affects higher thought processes; 2) why there is enormous individual variation in the behavioral effects; 3) what the relationship is between the immune system and psychological function; and 4) how personal and psychological factors (e.g., self-esteem) affects the mental health of HIV+ subjects, and may indirectly affect cognitive function.